Federal authorities have charged a NY man with building a 90 kilogram bomb they say he planned to detonate on Election Day on the National Mall in Washington.

Paul Rosenfeld, 56, appeared in federal court on Wednesday after law enforcement agents found an explosive device in his basement on Tuesday, according to a news release from the US Attorney's Office for the Southern District of NY.

Rosenfeld allegedly supported a political belief called sortition, which advocates for random selection of government officials.

He allegedly bought large quantities of black powder over the internet to build a large bomb in his basement, and had previously made and tested other small bombs.

"As alleged, (the man) concocted a twisted plan to draw attention to his political ideology by killing himself on the National Mall in Washington, D.C. - risking harm to many others in the process", U.S. Attorney Geoffrey S. Berman said.

Prosecutors say 56-year-old Paul Rosenfeld planned to detonate the explosive in Washington, hoping to kill himself and draw attention to his political beliefs.

Rosenfeld sent letters and text messages to a person in Pennsylvania ― identified by NBC News as a reporter ― in which Rosenfeld detailed his plan to blow himself up, authorities said.

"Police and Federal Bureau of Investigation agents searched a Hudson Valley, New York, home Wednesday and arrested the 56-year-old man living there after learning about his alleged plan to build a bomb and blow himself up in Washington, D.C., on Election Day, two law enforcement officials told News 4 New York", writes NBC.

Inside the home, agents also found a fusing system for triggering explosive devices and what appeared to be empty canisters of black powder. "Fortunately, his plans were thwarted by the quick action of a concerned citizen and the diligent work of a host of our law enforcement partners and the FBI's Joint Terrorism Task Force".

At a Senate hearing Wednesday morning, FBI Director Christopher Wray said his agents are investigating about 1,000 homegrown terror threats in all 50 states.

ROsenfeld was charged with unlawfully manufacturing a destructive device, which carries a maximum sentence of 10 years in prison.

Rosenfeld made his first appearance in NY federal court earlier Wednesday.